Menu authoring for automatically performing low-level DVD configuration functions

ABSTRACT

A DVD authoring system in a processor-based system removes an author from consideration of the DVD Specification during authoring. According to a preferred embodiment, the authoring system provides an authoring engine having an interactive graphical authoring interface, a data management engine, an emulator, a compiler, a multiplexer and a simulator. Using summary authoring data, the compiler builds a skeleton-form PGC layout structure comprising control PGC abstractions and router PGC abstractions. The compiler then resolves the PGC abstractions according to source-target connections. During playback on a DVD player, the PGC abstractions form elements in a connection-switching abstraction superstructure. Accordingly, in response to DVD-consumer and other control events, a source PGC preferably determines target PGC information and then transfers control, via virtual connections through necessary router PGC abstractions, to a target PGC abstraction. The target PGC abstraction then correspondingly initiates playback of a movie chapter or displays a menu.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Application is a continuation of application Ser. No. 09/010,267that was filed on Jan. 21, 1998 and titled “MENU AUTHORING SYSTEM ANDMETHOD FOR AUTOMATICALLY PERFORMING LOW-LEVEL DVD CONFIGURATIONFUNCTIONS AND THEREBY EASE AN AUTHOR'S JOB,” which issued as U.S. Pat.No. 6,453,459 on Sep. 17, 2002.

FIELD OF THE INVENTION

The present invention relates generally to mass data storage andretrieval, and more particularly to apparatus and methods for authoringa digital versatile disk.

BACKGROUND OF THE INVENTION

New mass data storage means provide not only for storing greater amountsof multimedia and other information, but also for more interactive dataretrieval by consumers. For example, one such storage means is espousedby the “DVD Specification for Read-Only Disc, Physical, File Format andVideo Specifications” (DVD Consortium 1997), hereinafter referred to asthe “DVD Specification”. Other examples include further DVD-relatedtechnologies (e.g. DVD-Audio, DVD-RAM, etc.) as well as non-DVDtechnologies.

The Physical and File System portions of the DVD Specification definesthe physical encoding and organization of data for storage on read-onlydigital versatile disk (“DVD ROM”) media. The Video portion of the DVDSpecification defines a data set (“DVD-Video data set”) with whichpre-recorded DVD-Video discs must conform in order to assure properreading, decoding and playback when inserted into a media reader/decoder(“DVD-player”). More specifically, the Video portion specifies how“control data” and audio/video “presentation data” are encoded andordered within the data set. The control data determines howpresentation of audio/video data will proceed when the disc is playedback on a DVD-player and consists of low-level state information, datastructures and instruction sets which govern what kinds of functions anduser operations a DVD player can perform.

The DVD Specification is further hereby fully incorporated herein byreference as if repeated verbatim immediately hereinafter.

The process of encoding and authoring a DVD movie title, as currentlypracticed, includes a number of separate and distinct steps requiringsimilarly separate and distinct expertise. After movie production, rawfilm and/or video footage is edited, the soundtrack is edited and mixed,and a movie film or video master is created. This master is subsequentlydigitized, encoded as video and audio streams and stored as data files.In accordance with the DVD Specification, the Moving Pictures ExpertGroup (“MPEG-1 or MPEG-2”) format is used to encode the video streamsand any one or more of a number of specified formats (e.g. MPEG-1 orMPEG-2 Audio, Dolby AC-3, PCM) is used to encode the audio streams.Graphic data (i.e. still or moving images for creating menus and otherpresentation data) is also created and stored in conventional graphicfiles. Finally, authoring guidelines, the encoded audio and video streamfiles and the graphic files are gathered for the authoring phase.

During authoring, a DVD author utilizes the guidelines and fileinformation to construct a DVD movie-title. The authored movie-titledetermines what a user of a resultant movie title will see and hear, andwhat kinds of interactions the user can command when the movie title isplayed back by a DVD-player. The author organizes the video, audio and(often author-created) subtitle files, divides the movie into segments(“chapters”), creates menus, and specifies low-level instructions. Thelow-level instructions will set parameters, define fixed or optionaljump points and their destinations and determine the order and optionsby which playback of still pictures, movie chapters and associated audiotracks will proceed based on the user's menu selections and/or use ofother DVD-player controls (i.e. typically using a remote controldevice).

Once authored, the author's organizational decisions, subtitle, chapterand menu decisions, and low-level instructions are compiled into controldata, and the encoded video, audio and subtitle streams, as well as thegraphic data files, are multiplexed into presentation data, whichtogether constitute the DVD-Video data set. Finally, this DVD-Video datais converted into a “disc image layout” file, which can be used to burna “write-once DVD-R” disc, or can be stored onto a tape to send to aDVD-ROM manufacturing plant for creating a “master” disc, which can thenbe used for replication.

Conventional DVD authoring systems comprise a computer system running anapplication-specific DVD authoring program. An exemplary, widely usedconventional DVD authoring system is Scenarist-II.

Scenarist-II is essentially an attempted, nearly direct embodiment ofthe DVD Specification. Using Scenarist-II, an author organizes datastreams, and constructs menus and DVD structures according to the DVDSpecification. Top level structures (i.e. up to 99 “VTSs” and “VTSMs”, a“VMG” and a VMGM”) are constructed by selecting the structure type andthen populating the structure with one or more low-level commandsegments (“program chains” or “PGCs”) including movie or menureferences. Throughout this process, the author also selects from amongavailable data formats, as well as from among the numerous DVD optionsand requisite parameters, using a number of provided lists and otherdata and parameter representations. Stated alternatively, all structuresand PGC parameters, capabilities and references must be fully specifiedby the author on an ongoing basis during authoring.

Unfortunately, the DVD Specification is very complex, as are theconventional programs that attempt to embody it. Available options areextensive, as are the numerous listings of options and parameters withinprograms such as Scenarist-II. The potential combinations of structuresand PGCs are also extensive, and many such combinations will notultimately result in functional DVD movie-titles.

To make matters more difficult, the PGCs (i.e. basic and frequentconstructs of the DVD Specification and therefore of programs such asScenarist-II) are counter-intuitive. Often, many PGCs (including bothoperative and so-called “dummy” PGCs) must be used in specificcombinations to provide a DVD consumer with even the most basic controlcapabilities. Limitations imposed by the DVD Specification must also beconsidered throughout the process. Thus, errors in planning and/orprogramming might well remain undetected until after a substantialnumber of structures are formed. In addition, given the sheer number ofstructures, PGCs, commands, options and parameters involved,identifying, locating and correcting errors is difficult andtime-consuming.

Consequently, while providing extensive low-level control and anexpedient authoring-to-compilation correspondence, conventionalauthoring systems require an extensive expertise with regard to both theDVD Specification and the authoring system itself. Further, evenassuming such expertise, authoring is extremely time-consuming and istherefore typically very costly. In addition, even assuming resolutionof other factors, the time and expertise required would likely preventauthoring of even a preliminary movie-title as a directorial aid duringthe movie production process.

A further disadvantage of conventional authoring systems is thatexperimentation and all but necessary modification are often compromiseddue to time and cost considerations. Thus, many DVD movie titles (due tolimited budget to support expensive authoring time) provide a DVDconsumer with only minimal playback control, navigation flexibility andinteractivity.

Accordingly, there is a need for an authoring system and method thatenables DVD authoring in a manner removed from the structures andlow-level instruction sets of the DVD Specification, thereby reducingthe time, cost and complexity of the authoring process.

There is further a need for such an apparatus and method wherebyauthoring can be conducted in an intuitive manner, while maximizingflexibility and access to features provided by or otherwise not inconflict with the DVD Specification.

SUMMARY OF THE INVENTION

The present invention provides a data processing-system based authoringsystem and method that essentially removes an author from considerationof the structures and low-level instruction sets of the DVDSpecification. More specifically, the present authoring system removesthe ordered tasks associated with creating DVD structures andprogramming PGCs, and replaces them instead with an interactive,intuitive and graphical authoring environment.

The present invention further provides for flexible program flow inresponse to control events. Many interactive controls, menu buttondestinations and other features that are possible in accordance with theDVD Specification can be specified by an author in multiple instancesand according to quick, intuitive and interactively modifiableselections. Thus the invention facilitates authoring of a DVD movietitle by even an inexperienced author with context sensitiveresponsiveness to DVD consumer instructions and other DVDplayer-generated events.

Accordingly, a preferred embodiment of the present invention comprisesan authoring engine having an integrated interface with which an authorperforms the above tasks a data management engine for storing andrecalling authoring information, a simulator for viewing progressiveand/or comparatively authored movie titles prior to compiling, acompiler, a multiplexer and an emulator for viewing authored movietitles after compiling and multiplexing.

Included within and facilitating the ability of these elements to removean author from the DVD Specification are several abstractions.Preferably, the interface provides such “user abstractions” as arrangingmovies (i.e. data streams including video, audio, subtitles, chapterpoints and other elements), creating menu layouts (i.e. menus, menubuttons and still or moving images with or without sound) and specifyingconnections among these arrangements and layouts, each in a simple andintuitive, yet highly flexible way. Further abstractions include anetwork or connection-switching abstraction and a number of control androuter PGC abstractions from which the connection-switching abstractionis constructed.

Authoring instructions entered through the interface are preferablybroken down into component parts and stored by the data managementengine. The invoked compiler, using only summary authoring information,preferably constructs a skeleton form PGC layout structure comprised ofPGC abstractions corresponding to the number of authored movie elements.The compiler then completes the layout structure according toauthor-selected and default source-target connections.

Further according to a preferred embodiment, during playback of aresultant DVD movie title, a source PGC abstraction is invoked inresponse to DVD player and/or consumer instructions. The source PGCabstraction determines target information and transfers control, throughnecessary router PGC abstractions, to a target PGC abstraction. Thetarget, in accordance with the target information, plays a moviechapter, displays a menu, or sets and/or modifies one or more DVDparameter.

These and other objects, advantages and benefits of the presentinvention will become apparent from the drawings and specification thatfollow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is functional block diagram generally illustrating an authoringsystem according to a preferred embodiment of the invention;

FIG. 2 is a functional block diagram illustrating in more detail apreferred authoring program of the authoring system shown in FIG. 1,according to the invention;

FIG. 3 is a screenshot of a preferred performance element arrangementinterface portion of the FIG. 2 authoring program, according to theinvention;

FIG. 4 is a blowup of the FIG. 3 screenshot showing, in more detail, apreferred authoring toolbar for accessing authoring program modules andfunctions;

FIG. 5 is a flowchart illustrating an exemplary method used by an authorto create a performance element arrangement using the performanceelement arrangement interface portion of FIG. 3;

FIG. 6 a is a flowchart illustrating preferred responses of theauthoring program to authoring while the performance element arrangementinterface portion of FIG. 3 is active;

FIG. 6 b is a flowchart further illustrating preferred responses of theauthoring engine to authoring while the performance element arrangementinterface portion of FIG. 3 is active;

FIG. 7 is a screenshot of a menu element layout interface portion of theFIG. 2 authoring program, according to the invention;

FIG. 8 is a flowchart illustrating an exemplary method used by an authorto create a menu layout using the menu element layout interface portionof FIG. 7;

FIG. 9 is a screenshot of a preferred connections interface portion ofthe FIG. 2 authoring program, according to the invention;

FIG. 10 is a screenshot of a preferred simulator interface portion ofthe FIG. 2 authoring program, according to the invention;

FIG. 11 is a functional block diagram of a preferred data managementengine according to the invention;

FIG. 12 a is a flowchart showing generally the operation of a preferredcompiler according to the invention;

FIG. 12 b is a flowchart showing how a compiler according to theinvention preferably constructs a skeleton-form PGC layout structure;

FIG. 12 c is a flowchart showing how the compiler preferably resolvessource-target connections and substitutes those connections for nulloperations in a preferred skeleton-form PGC layout structure, accordingto the invention;

FIG. 13 is a block diagram showing the format of a preferred PGC layoutstructure according to the invention;

FIG. 14 is a functional block diagram showing a preferredconnection-switching abstraction according to the invention;

FIG. 15 is a flowchart showing a preferred operation of theconnection-switching abstraction of FIG. 14, according to the invention;

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

For clarity sake, the discussed embodiment herein will be directedprimarily toward storage according to the DVD Specification, and morespecifically at authoring motion picture DVD ROMS (“movie titles”). Itshould be understood, however, that the present invention relates to abroad range of program and data storage and retrieval utilizing avariety of media, only a subset of which will be specifically identifiedherein. The types of DVD ROMS which can be authored are further in noway limited to movie titles. Other examples include but are not limitedto music videos, documentaries, educational videos, corporate training,medical applications and other continuous play or interactiveinformation which utilizes audio, video and/or other presentation data.

As illustrated in FIG. 1, a preferred embodiment of authoring system 100according to the invention preferably comprises electrically connectedhardware elements including input devices 110, processor 115, memory120, storage 125, MPEG encoder/decoder 130, video I/O device 135 andaudio I/O device 140. Authoring system 100 further comprises softwareelements including operating system 150, authoring engine 160, datamanagement engine 165, compiler 170, simulator 175, emulator 180 andmultiplexer 185.

It will be apparent to those skilled in the art that several variationsof the authoring system elements are contemplated and within theintended scope of the present invention. For example, given processorand computer performance variations and ongoing technologicaladvancements, hardware elements such as MPEG encoder/decoder 130 may beembodied in software or in a combination of hardware and software.Similarly, software elements such as multiplexer 185 may be embodied inhardware or in a combination of hardware and software. Further, whileconnection to other computing devices is indicated as network I/O 145,wired, wireless, modem and/or other connection or connections to othercomputing devices (including but not limited to local area networks,wide area networks and the internet) might be utilized. A furtherexample is that the use of distributed processing, multiple siteviewing, information forwarding, collaboration, remote informationretrieval and merging, and related capabilities are each contemplated.Various operating systems and data processing systems can also beutilized, however at least a conventional multitasking operating systemsuch as Windows95® or Windows NT® (trademarks of Microsoft, Inc.)running on an IBM® (trademark to International Business Machines)compatible computer is preferred and will be presumed for the discussionherein. Input devices 110 can comprise any number of devices and/ordevice types for inputting commands and/or data, including but notlimited to a keyboard, mouse, and/or speech recognition. (The use of akeyboard and a mouse are exemplified throughout the discussion thatfollows.)

The FIG. 2 block diagram illustrates in greater functional detail anauthoring program 201 of the preferred authoring system of FIG. 1. Asshown, authoring program 201 comprises authoring engine 160 (whichincludes interface 160 a), data management engine 165, compiler 170,simulator 175, emulator 180, multiplexer 185, output DVD data storage290 and layout formatter 187, user abstractions 285 and PGC abstractions287.

It is discovered through examination of the features supported by DVDplayers that the basic presentation data types and consumer controlsavailable to an author of DVD movie titles can be generalized and thenreconstructed as abstracted user data types and controls. Further,despite the complexity of the DVD Specification, many of its programmingconstructs can also be generalized and then reconstructed as abstractedDVD program chains (“PGCs”) operating within a further abstractednetwork or connection-switching superstructure. Such user abstractions285 and PGC abstractions 287, as integrated into authoring engine 160,data management engine 165 and compiler 170 (as illustrated),effectively remove an author using authoring program 201 fromconsideration of DVD Specification 205. These abstractions furtherremove such consideration without unduly limiting, for most practicalpurposes, authoring flexibility, PGC efficiency or interactiveresponsiveness of a resultant DVD-ROM, among other factors. In addition,these abstractions provide a framework of re-useable components that arereadily adaptable to further modification for providing improvements,and for re-use in a variety other DVD and non-DVD applications.

Authoring program 201 is preferably implemented in C++, anobject-oriented language, for reliability, updateability and other knowngeneralized advantages of object-oriented programming. Those skilled inthe computer arts will appreciate however, that despite such advantages,other environments and/or programming languages of variousobject-oriented and non-object-oriented types can also be utilized.

Operationally, an author enters authoring information and instructionsfor activating and controlling authoring program 201 through interfaceportion 160 a of authoring engine 160. Authoring engine 160interactively receives entered information and commands bycorrespondingly adjusting interface portion 160 a, invoking a furtherauthoring program module, sending entered authoring information to datamanagement engine 165, retrieving authored information from datamanagement engine 165, and sending and/or retrieving presentation datafrom presentation data storage 203. Data management engine 165 respondsto authoring engine 160 by receiving and storing authored informationfrom authoring engine 160 and/or sending information, which it retrievesfrom storage (and/or from a remote source), to authoring engine 160.Simulator 175 responds to authoring engine 160 by retrieving authoringdata from data management engine 165, retrieving multiplexedpresentation data from multiplexer, and simulating an authored DVD-ROMin conjunction with interface 160 a.

Compiler 170 responds to authoring engine 160 by retrieving authoredinformation from data management engine 165, compiling the informationand storing the compiled information (“.ifo files”) in output DVD datastorage 290. Emulator 180 responds to authoring engine 160 by retrievingcompiled data from output DVD data storage 290, retrieving multiplexeddata from output DVD data storage 290 and emulating an authored DVD-ROMin conjunction with interface 160 a. Multiplexer 185 responds toauthoring engine 160 by receiving DVD parameter information fromcompiler 170, retrieving presentation data from presentation datastorage 203 and combining the retrieved information and data inaccordance DVD Specification 205. Multiplexer 185 then stores thecombined information and data (“DVD data stream” or “.vob file”) inoutput DVD data storage 290. Layout formatter 187 retrieves the .vobfiles and .ifo files from output DVD data storage 290 and combines thesefiles into a single “disc image” file, which it then stores in discimage file storage 207. The disc image file can then be sent throughnetwork I/O 145 (FIG. 1) to additional apparatus for further review,processing and/or for burning one or more DVD-ROMs 207.

FIGS. 3 through 10, with reference to FIG. 2, illustrate how aninterface according to the invention enables an author to assemble amovie title essentially removed from DVD programming specifications 207(FIG. 2) of the DVD Specification. Preferred interface 160 a isillustrated as an application running under a Windows95® or Windows NT®(trademark of Microsoft, Corp.) operating system.

The FIG. 3 screenshot illustrates a preferred authoring window 300,which an author can utilize to select an arrangement of audio-visualmaterial including video segments (“video clips”), audio segments(“audio clips”) and subtitles (hereinafter referred to collectively as“performance data”).

Authoring window 300 is divided into movable, modifiable and replaceablegroupings or “views” and “panels” including presentation data panel 301,performance assembly panel 302, assembled elements panel 307, log panel308 and preview video panel 309. Assembly panel 302 is further dividedinto video assembly portion 320, audio assembly portion 330 and subtitleassembly portion 340 (which are collectively referred to herein asperformance view 303), and performance tools portion 360. Authoringwindow 300 also includes authoring toolbar 399 a and menu bar 399 b. Forclarity sake, the following discussion assumes that a single, continuousmovie is being authored (i.e. a movie having component video, audio andsubtitle data streams each of which begins at the start of the movie andends at the conclusion of the movie).

Presentation data panel 301 provides a display listing for eachpresentation data file that an author has selected and loaded for use inassembling movies and menus either during a current authoring session orwhen continuing a re-initiated, prior authoring session. File listingsinclude file name 311, file duration 313, and file type 315 parameters.File name 311 lists the name of a file. File duration 313 lists theplayback duration of files such as video data files and audio datafiles. File type 315 alternatively lists a file format, which isgenerally indicated by a filename extension, or a recognized data typesuch as “video” data or “audio” data. As will be further discussed,presentation data file listings can be used interactively during anauthoring session.

Performance assembly view 303 of performance assembly panel 302 is usedby an author to graphically and interactively assemble loaded videoand/or audio data, to add and assemble subtitles, and/or to add chapterpoints. For these purposes, performance view 303 includes video assemblyportion 320, audio assembly portion 330, subtitle assembly portion 340and chapter assembly portion 350 respectively. Video assembly portion320 is used by an author to assemble graphic objects referencing storedvideo data files (“video clips”). As discussed, these files, onceinitially selected, are listed in presentation data panel 301. Videoframe thumbnails 323 a and 323 b are indicative of chapter points aswill be further discussed herein.

Audio assembly portion 330 of performance assembly panel 302 is used byan author to receive graphic objects referencing stored audio data files(“audio clips”). As with video clips, audio clips, once selected foruse, are listed in and selected from presentation data panel 301 forarrangement purposes. Up to eight (alternate language) audio datastreams or audio “tracks”, exemplified by audio tracks 331 a through 331c, are available in accordance with DVD Specification 205 (FIG. 2).Audio bars 332 a and 332 b, which represent author-arranged audio clips,have a length that reflects the playback time of the audio datarepresented. Separators 333 are further indicators of chapter points, aswith video frame thumbnails 323 a and 323 b of video assembly portion320. Audio tracks 332 a through 332 c further include audio encodingindicators 334 a, audio format indicators 334 b, track number indicators335 and selected language indicators 336, which are indicativerespectively of audio data file encoding and playback format, selectableaudio track number 336 and modifiable language label 335. Languagelabels 335 can be set by author selection or, as is expected,automatically by recognition of languages spoken in a recorded dialog ofa respective audio track.

Subtitle assembly portion 340 provides for entry, retrieval and/orediting of up to thirty-two (alternate language) frame-based subtitlesequences, as exemplified by tracks 341 a and 341 b. Exemplary subtitleframes 342 a and 342 b illustrate textual subtitle contents. Subtitlesare entered in a conventional manner using a conventional text editor(not shown) which is invoked by activating a subtitle frame (e.g. bymenu selection or double-clicking) and/or by retrieving a pre-existingsubtitle file using, for example, presentation data panel 301. As withaudio assembly portion 330, subtitle portion 340 includes selectabletrack numbers and modifiable language label indicators.

Performance assembly view 303 also includes chapter assembly portion350, which is used by an author to graphically and interactivelyassemble chapter points. Chapter assembly portion 350 includes wallclock 351, reference offset clock 352, author-assembled chapterindicators 353 a through 353 c, chapter time indicators 354 a through354 c and reference time indicators 355 a through 355 c. Wall clock 351indicates a time within a video clip corresponding to a cursor positionover chapter portion 350 of assembly panel 302. Offset clock 352indicates the start time of a currently indicated video clip accordingto the reference timecode of a master tape (i.e. from which the videodata file was created). Chapter indicators 353 a through 353 c showchapter points (i.e. points to which a DVD-ROM consumer can advance) asarranged during authoring. Chapter time indicators 354 a through 354 cand reference time indicators 355 a through 355 c display the elapsedtime of corresponding selected chapter points from the start of a movieand from the start of a clip respectively. Reference times are typicallyrecorded (and thus can be selectively retrieved and displayed) utilizingSociety of Motion Pictures and Television (“SMPTE”) timecode.

As noted earlier, performance assembly panel 302 and the other panelsand views of authoring window 300 are replaceable. Tabs 302 a provideone alternative control structure for selectively switching betweeninitiated or “open” authoring tasks, for example, to alternate betweenassembling presentation data of multiple movies, for creating menulayouts, and/or for other authoring tasks. Other control structuresinclude menu options (not shown) for selectively de-coupling panels andtransport enabling controls (362 a through 362 c and 363 a through 363b), and further for re-coupling in the illustrated default arrangement,in an author-selectable arrangement and/or interactively by an author.Panels can be resized and/or re-arranged among other windowcapabilities, as will be understood by those skilled in the art in viewof the discussion herein.

Assembly tools portion 360 of performance assembly panel 302 comprisesselectable zoom controls 361 a through 361 c, preview transport buttonsincluding stop 362 a, play 362 b and frame advance 362 c, previewtransport start time selector 363 a and stop time selector 363 b,selected clip indicator 364 a and total clips indicator 364 b. Zoomcontrols 361 a through 361 c are used respectively for increasing theviewable data range of a selected area within performance assembly view303 of performance assembly panel 302, for selecting a portion ofperformance assembly view 302 for such viewing, and for decreasing theviewable data range. Transport controls 362 a through 362 c providevideo playback control when previewing a video clip, audio clip and/orsubtitle data using preview video panel 309, or when selecting arepresentative video frame in a video clip as a preview thumbnail (aswith exemplary thumbnails 323 a and 323 b). Transport control 362 ahalts video, audio and/or subtitle playback, transport control 362 binitiates/continues playback and transport control 362 c provides forper-frame (“step”) viewing, as will be understood by those skilled inthe art. Start and end time selectors 363 a and 363 b are usedrespectively for selecting and monitoring video, audio and/or subtitleplayback position and for setting and monitoring a playback stop time.

Assembled elements panel 306 provides interactive and selectablelistings of authored contents of a current movie title, including butnot limited to movie volume 361, movies 362 and menus 363.

Log panel 308 provides selectable progress reports and other informationrelating to decoding/encoding of presentation data, compiling and layoutof a disk file format according to DVD disk format specifications 205(FIG. 2). These reports are automatically created and can be accessedusing log tabs exemplified by tabs 381 and 383.

Preview video panel 303 selectively displays a video frame correspondingto a cursor position over assembly panel chapter portion 350, videoassembly portion 320, audio assembly portion 330, subtitle portion 340and/or chapter portion 350 of assembly panel 302. In addition, previewvideo panel is used for previewing video data using transport controls362 a through 362 c, start and stop time selectors 363 a and 363 b ordirectly invoking the panel using selection or drag-and-dropcapabilities. (As will be understood by those skilled in the art,encoded video and audio files are decoded and buffered, as needed, forplayback in a conventional manner using MPEG encoder/decoder 130 of FIG.1.)

The following toolbar chart lists the respective elements of toolbar399. It will be understood by those skilled in the art, in view of thediscussion herein, that the toolbar elements can vary substantially andincludes user-defined expandable and replaceable elements. The elementsshown are provided as defaults.

Label Referenced as Description 401 New volume Loads default values andadjusts the interface for a new movie title. 403 New menu Loads defaultvalues and adjusts the interface for a new menu layout. 405 New movieLoads default values and adjusts the interface for authoring a newmovie. 407 Connections Switches to an existing connections interface oradjusts the interface, according to default values for initially settingconnections. 413–415 Cut, copy and paste Provide conventional functionsexcept as described herein for connections. 421 Compile start Initiatingcompiler operation. 423 Compiler stop Interrupts compiler operation. 425DVD Layout Invokes DVD Disk layout operation. 427 Write Tape Providesfor output of multiplexed data stream to tape. 429 Simulator Invokessimulator

The FIG. 5 flowchart illustrates, by way of example and with referenceto FIGS. 3 and 4, how an interface in accordance with the inventionenables an author to assemble performance data and objects withoutconsideration for structures, commands or ordered tasks imposed by DVDprogramming specifications 207 (FIG. 2). Select, open and drag-and-drop,among other operations, and clicking, double-clicking, click-and-dragand other user actions associated with graphic interfaces are well knownand will not be further expounded upon herein.

As shown, in step 505, an author initiates a new project (“volume”) byselecting new volume 401 (FIG. 4). In step 510, the author initiates anew movie by selecting new movie 405. In step 515, the author adds videoand audio files to presentation data panel 301 (FIG. 3) for potentialuse in the volume by movies and menus. In step 520, the author canpreview a video file in preview panel 304 by dragging its icon inpresentation data panel 301 to preview panel 304 and/or, if desired, byinvoking transport controls 362 a through 362 c, preview timer 393and/or other playback-related controls. In step 525, the author adds aselected video clip to the currently opened movie by double-clicking itsicon in presentation data panel 301 or by dragging the icon frompresentation data panel 301 to video assembly portion 320 of performanceview 303. In step 530, the author can select a video frame thumbnailother than a first frame for reference viewing by dragging the pointerof thumbnail timer 325 a and/or by using transport controls 362 athrough 362 b.

In step 535, the author can preview an audio file by selecting its iconin presentation data panel 301 and using controls including stop 362,play 362 b, using start time and end time selectors 363 a and 363 band/or using other play-related controls. In step 540, the author adds aselected audio clip to a next available track of the currently openedmovie by double-clicking its icon in presentation data panel 301.(Alternatively, the author can add a selected audio clip to a specificaudio track by dragging the icon from presentation data panel 301 to aselected track in audio assembly portion 330 of performance view 303. Instep 545, the author selects a language label by selecting selectedlanguage indicator 335 and selecting a listed element.

In step 550, the author opens a subtitle frame and enters subtitleinformation for display in a video frame during playback of video clips.In step 555, the author selects a language label corresponding to thesubtitle track containing the subtitle frame. If, in step 560, theauthor elects to add more performance data, then the author returns tostep 520.

In step 565, the author moves a cursor within chapter assembly portion350 of performance view 303 to view video frames available as chapterpoints. In step 570, the author selects a chapter point. If, in step575, the author elects to add more chapter points, then the authorcontinues at step 565.

In step 580, the author selects an audio track number and optionallyselects a subtitle track number and/or playback start and/or end timesbefore selecting play button 362 b to preview playback of the video clipand the audio clip referenced by the selected track number.

The FIGS. 6 a and 6 b flowchart (with reference to FIGS. 2 and 3)generally illustrates responses by the preferred authoring program 201to an author's actions according to the invention. As shown, if in step602 an author selects a movie assembled in a prior authoring session,then, in step 604, data management engine 165 (FIG. 2) loads relatedparameters and, in step 606, sends the parameters to authoring engine160. Otherwise, default parameters for a new movie are loaded in step608.

In step 609, authoring engine 160 updates assembled elements panel 307(FIG. 3) and other affected interface 160 a elements to indicate themovie parameters. If, in step 612, the author selects presentation datafiles, then data management engine 165 loads and sends the respectivepresentation data file parameters to authoring engine 160 in step 614,which updates presentation data panel 301 in step 616. If, in step 622,the author assembles one of the selected video clips, then authoringengine 160 accordingly updates video assembly portion 320, chapterassembly portion 350 and offset clock 352 in step 624, updates assembledelements panel 307 in step 626, and sends the video clip parameters todata management engine 165 for storage in step 628. Similarly, if theauthor assembles one of the selected audio clips in step 632, thenauthoring engine 160 updates the selected track of audio assemblyportion 320 in step 634, updates assembled elements panel 307 in step636, and sends the audio clip parameters to data management engine 165in step 638. If, in step 642, the author assembles subtitle data, thenauthoring engine 165 updates subtitle assembly portion 340 in step 644,updates assembled elements 307 in step 646, and sends subtitle data andparameters to data management engine 160 in step 628.

If, in step 652, the author moves an interface 160 a pointer (e.g. amouse pointer) within chapter assembly portion 360, then in step 654authoring engine 160 updates wallclock 351, finds an I-frame (i.e. avideo frame that is completely described without reference to otherframes) within the video clip corresponding to the mouse pointerposition and displays the I-frame in preview video panel 309. If, instep 672, the author assembles a chapter point, then authoring engine160 updates video assembly portion 340 and chapter assembly portion 350in step 674, updates assembled elements panel 307 in step 676, and sendscorresponding chapter parameters to data management engine 165 in step678.

The FIG. 7 screenshot illustrates the preferred authoring window 300 ofFIG. 3 with the performance data assembly panels replaced by panels forallowing an author to layout menus. More particularly, menu layout panel701 and menu tools panel 702 are selected, sized and positioned toreplace performance view 303 of FIG. 3. An exemplary menu layoutincluding graphic and textural images is shown in menu layout panel 701for purposes of illustration. Menu layout panel 701 is used visually andinteractively by an author to retrieve, add, place and modify menuelements using menu tools panel 702 selections.

In accordance with the DVD Specification, menu elements presentable to aDVD consumer can include a background image (“background”), an overlayimage (“subpicture”) and up to twenty-five buttons. For the presentexample, author-selected background 710 is a multicolor design, andauthor-selected subpicture 711 includes the textural information, DolbyDemo 1, Dolby Demo 2, Play Both Demos and Main Menu. Four author-createdbuttons 720 a through 720 d including button frames 721 a through 721 dare also shown. Each of button numbers 722 a through 722 d is added byauthoring program 201 (FIG. 2) in response to creation of a respectivebutton for identification purposes (i.e. during authoring and for use incompilation).

Menu tools panel 702 comprises controls for implementing selectable menuelement parameters and for selectably altering the displaycharacteristics of elements within menu layout panel 701 during anauthoring session. For example, color selection boxes 732, 734, 736 and738 allow an author to choose a button outline color for display (in aconsumer viewing scenario) when a button is not selected (“normal”),when a consumer points at the button (“selection”) and when a button isinvoked (“action”) respectively. An author can also select the opacityof the buttons for these cases using opacity sliders 733, 735, and 737respectively. Similarly, an author can select button shapes and othercharacteristics by selecting one of the layout feature tabs 739 andutilizing the tool sets that appear in a respective tool set panel (notshown). An author might, for example, utilize prior button shape, color,texture, opacity and/or normal, selection and activation colorcombinations used with a prior authoring session as either a startingpoint for further changes or without further modification. Otherparameter combinations might also be utilized. Safe area toggle 755 aallows an author to selectively display safe area indicator 755 b ofmenu layout panel 701 (which bounds an area that is assured to bedisplayed on a consumer television). Display controls 751 and 752provide for altering the characteristics indicated which, in light ofthe prior discussion, will be understood by those skilled in the artwithout further edification.

Layout feature tabs 749 also provide access to button ordering tools(not shown). As with other authoring parameters, an author canselectively utilize an existing order of buttons that will be traversedin a currently displayed menu when a consumer pushes directional buttonson a remote control device. An alternative order can also be set usingany number of methods including but not limited to using a displayedremote control device or dragging an arrow from a starting point to anending point. Such features and their operational characteristics, giventhe foregoing, will be understood by those skilled in the art withoutfurther edification.

The FIG. 8 flowchart shows how the actions required for laying out amenu are consistent with those for assembling performance data. Onceagain, authoring is visually and interactively achieved withoutrequiring any specific ordering of actions. Therefore, as withperformance data assembly, the specific ordering of actions is given forpurposes of illustration only.

As shown, in step 805, the author selects background and subpicturefiles for inclusion in a menu layout. Selected files will appear inpresentation data panel 301 (FIG. 7). In step 810, an author adds abackground and a subpicture to the current menu by double-clicking onfile listings, dragging the files to menu layout panel 701 or by using asimilar method. In step 815, the author draws (i.e. drags a box) aroundsubpicture text forming a button frame, thereby indicating buttonplacement directly in menu layout panel 701. If, in step 820, morebutton frames remain to be added, then the author returns to step 815.

In step 825, the author selects a button and sets shape, size, opacityand other parameters using preset combinations and/or color selectionboxes 732, 734, 736 and 738, opacity sliders 733, 735, and 737 and/orother tools. In step 830, the author sets the intra-menu button order inthe manner already described. If, in step 840, more menus remain to becreated, then the author selects add menu button 413 in step 840, andreturns to step 805. New elements appear in assembled elements panel 307and control data (i.e. relating to added elements and their layoutcharacteristics) are sent to data management engine 165 (FIG. 2) as withperformance data assembly.

The FIG. 9 screenshot illustrates a further selectable configuration ofthe FIG. 3 interface for linking together presentation data, menulayouts, buttons within menu layouts and available control functions ofa DVD player. As shown, connection view 901 includes available targetspanel 903 and linking panel 905. Linking panel 905 further includesavailable sources portion 950 and connected targets portion 960. Whileconnections view 901 is active, assembled elements panel 307 can furtherbe used as a selection means for navigating more quickly to a desiredtarget within available targets panel 903.

Operationally, an author forms a link or “available connection” simplyby copying (i.e. performing a copy action or dragging) a target fromavailable targets portion 903 to a position in connected targets portion960 that is in the same row as a desired source in available sourcesview 950. As with assembling a movie and menu layouts, an author caninteractively remove, move or otherwise modify links in a conventionalmanner. For example, a link can be removed by deletion or a target canbe moved or copied to another row in linking portion 905.

As with arranging performance data and forming menu layouts, an authorhas easy and complete flexibility in adding interactivity to aconsumer's viewing experience. A DVD movie can be authored, for example,such that entry and exit from a menu can be controlled by any availableevent. Referring also to the FIG. 10 simulator window 1000, any menubutton can further be linked to any DVD event, including but not limitedto a chapter point (e.g. chapter point 953), the end of chapter playbackor depressing a DVD remote control device menu button 1020 and 1040(FIG. 10). A particular menu button can also be used as a target inmultiple instances, as might be creatively appropriate.

Thus, for example, a consumer interface can be quickly and easilycreated which is interactively responsive (“context sensitive”) to aconsumer's actions. Stated alternatively, an interface can be authoredsuch that, for example. the conclusion of a specific chapter playback ormenu button activation will determine a next chapter playback, a nextmenu or even a next menu wherein an author-selected menu button ishighlighted.

Among the reasons for such ease and flexibility is that, contrary toconventionally authored DVD movies, program chains are not createdduring the authoring process. Similarly, connections specified duringauthoring are not permanent (“hard wired”). Rather, program chains arenot created until compilation and available connections are not fullyresolved until playback, each according to additional abstractions ofthe invention, as will be further discussed herein.

The FIG. 11 block diagram illustrates the structure of a preferred datamanagement engine 165 (FIG. 1) according to the invention. Asillustrated, data management engine 165 only partially reflects theinterface constructs and the structures of the DVD Specification. Whilereflecting interface abstractions (e.g. a movie, menu and connectionbased movie-title description) and DVD Specification requirements (e.g.first play jump source), data management engine 165 is furtherstructured as a flexible network of data storage and distributionobjects that also reflects other abstractions of the invention.

One further abstraction, for example, is a model of a DVD player, aconsumer's controller and the compiled authoring instructions as anactively connection-switched network. Within this network, DVD programchains representative of action-oriented authoring instructions(“routers”), perform switching among available connections in responseto DVD-player (i.e. consumer) instructions, thereby re-directing programflow and control. Control-receiving program chains then perform morelocalized tasks (e.g. such as displaying a menu). Stated alternatively,a router program chain resolves an available connection from aDVD-player control instruction to a receiving program chain, which againroutes control or executes the instruction. Further abstractions alsoinclude models of program chains for performing a common basefunctionality in a same or similar manner using a derived common programchain structure.

Such an arrangement provides real world flexibility and efficiency. Forexample, data management engine 165 supports authoring flexibility withregard to source-target connections that are switchable. Further, giventhe power of even conventional computer systems, data management engine165 is sufficiently robust to enable the interactive operation ofinterface 160 a (FIG. 2) as well as minimal compilation times ofcompiler 170 (i.e. only milliseconds) without direct interface or DVDprogram specification 205 correlation. Data management engine 165 istherefore also readily adaptable to interface variations and furtherinterfaces, as well as to compiler variations and other compilerssupporting other DVD and non-DVD data storage and/or retrievalapplications.

Referring again to FIG. 11 and with further reference to FIG. 2, datamanagement engine 165 comprises a root volume object 1100, which managesdata management engine 165 communication and storage. Volume object 1100provides an interface for communicating messaged data to and from itscomponent parts, including title key jump source 1101, first play jumpsource 1102, media database 1103, DVD layout properties 1104, movieslist 1105, menus list 1106 and connections list 1107 (objects). Mediadatabase 1103 further includes media files list 1130, which storespointers to media files referred to by the performance data arrangementas a result of authoring.

In addition, each of the presentation data objects (i.e. movies list1105 and menus list 1106) and a connection sets list object 1107 containlinks to other data management engine objects in the form of an objecttree. More specifically, movies list 1105 is linked to movie objectsmovie-1 1150 a through movie-M 1150 b, wherein M is the total number ofmovies authored for storage on a single DVD-ROM (“movie title”). Eachmovie object contains a respective track list object 1151 and arespective chapter list object 1152. Each track list object 1151contains respective track objects, track-1 1153 a through track-T 1153b, wherein T is the total number of tracks authored within a respectivemovie. Track-1 through track-T further contain clip lists, which in turncontain clip objects clip-1 1154 a through clip-CL 1154 b (and whereinCL is the total number of clips in a given track within a given movie).Finally, each clip object contains a respective clip properties object,as exemplified by clip object 1155.

Menu objects are structured in a manner similar to that of movieobjects. Menus list object 1160 contains menu objects menu-1 1160 athrough menu-N, wherein N is the total number of menus authored forstorage on a given DVD-ROM. Each menu object further contains arespective button list object (e.g. object 1161), each button listobject contains a respective button objects (button-1 1162 a throughbutton-B 1162 b) and each button object is linked to a button propertiesobject (e.g. object 1163). B indicates a total number of buttons in arespective menu.

Finally, connections sets list 1107 contains respective connectionslists (i.e. connect-list-1 1170 a through connect-list-CL 1170 b),wherein CL is the total number of connections lists authored for storageon a given DVD-ROM. Each connect-list is further linked to respectiveconnections objects (i.e. connect-1 1171 a through connect-CN), whereinCN is the total number of connections authored to facilitate flexibleprogram flow and control. Each connections object (1171 a through 1171b) represents an action-oriented switch between a respective source anda respective target (as indicated by source-pointer variable 1172 andtarget-pointer variable 1173), as will be discussed further herein.

Where applicable, each object includes an indexed object list having apointer to each connected dependent object (i.e. an object “further downthe tree” as illustrated), as well as a totals variable. The object listis updated to include new dependent objects as these objects are created(“instantiated”) to reflect, for example, an added chapter point ormenu. Dependent objects are similarly removed from the object listaccording to authoring deletions. Totals variables are also updatedduring authoring to reflect each corresponding dependent objectinstantiation and deletion. Undo and redo operations are handled in aconventional manner using authoring instructions which are furtherconventionally stored within respective objects during each authoringsession.

Using this structure, data management engine 165 breaks down or filterscontrol data generated during authoring into its basic component partsfor storage in a corresponding object's indexed data list. These basiccomponent parts are then retrieved by authoring engine 160, or retrievedand reconstructed into an applicable form by compiler 170, as needed.

Operationally, data management engine 165 receives messages fromauthoring engine 160 in response to and reflecting each authormodification of a performance assembly, menu layout or connection.Volume 1100 receives the message, polls its contained-objects list for arecipient object according to the message type, and sends the message tothe matching recipient object. If the message includes a reference to atitle key source or a first play source (which is author-slectable inconnections view 901), then volume 1100 sends the message respectivelyto either title key jump source 1101 or first play jump source 1102.Upon receipt, title key jump source 1101 or first play jump source 1102will accordingly store included data, delete stored data or modifystored data.

If a received message includes a reference to a video, audio or subtitlefile, then volume 1100 sends the message to media database 1103. If themessage contains an instruction to add a data element, then mediadatabase 1103 stores the data (which will include a pointer to a mediafile) in media files list 1130. If the message contains an instructionto delete a stored pointer, then media database 1103 deletes thepointer. If the message contains an instruction to modify a storedpointer (e.g. if the file was moved to a new location), then mediadatabase 1103 locates and replaces the file pointer. Media database 1103further updates its totals variable to reflect additions and deletions.

If a received message type relates to the content of a moviearrangement, menu layout or connection, then volume 1103 sends themessage respectively to movies list 1105, menus list 1106 or connectionslist 1107. Each of movies list 1105, menus list 1106 and connection setslist 1107 operates similarly to objects described thus far. Each parsesthrough a received message for included control information, sends themessage respectively to a corresponding movie object, menu object orconnections list and adjusts its totals variable as needed.

A movie message, for example, will then progress down through the movieobject tree, and, depending upon the message type, will be filtered, bytrack list 1151, track-1 1153 a and then handled a matching clip, orwill be filtered by chapter list 1152 and then handled by correspondingchapter or by a clip properties object (i.e. as illustrated). Menulayout data will similarly progress (as illustrated) down through themenus list tree, being handled by a matching menu properties object, andconnections data will progress down the connection sets list tree untilit is handled by a connection object (with reference to its sourcepointer or destination pointer variables). Upon receipt, a clipproperties, menu key, end key, menu properties or connection object willhandle the message and store included data, delete stored data or modifystored data in a similar manner as with media database object 1103.

Each respective storage object stores authoring modifications in asequentially indexed list according to its type (i.e. each object nameis illustrated to reflect the data type the object stores). Thus, forexample, chapter points within a movie are stored from a first chapterpoint during playback to a final chapter point in the movie. (Playbackwill however, be determined by authored connections.) The listaccommodates added, inserted or deleted data interactively by expandingor contracting about the addition, insertion or deletion point.

While other data structures might be utilized, interactively adjustedindexed lists and limited object definitions, using even a minimallyequipped computer, are sufficiently robust to accommodate an author'sinput rate, given the relatively small amount of data stored in eachlist. Alternative structures that might be used, for example, includebut are not limited to a lesser number of objects each containing a lessrestricted dataset and/or the addition of summary objects for storingtotal numbers of menus, buttons and system other status and/orstatistical information. Such arrangements however, have been found toadd complexity with only moderate gains in application-specificoperational characteristics. Alternative data structures, including butnot limited to multi-dimensional arrays, multiple queues and linkedlists stored locally and/or remotely, present similar tradeoffs.

Data management engine 165 returns stored data to authoring engine 160in a manner essentially the reverse of that for storing data. Volume1100, upon receipt of a request for stored data, parses the request callfor a data type, searches its contained objects list for a correspondingobject, and forwards the request to title key jump source 1101, firstplay jump source 1102, media database 1103, DVD layout properties list1105, movies list 1106, menus list 1107 or connection sets list 1107.Movies list 1105, menus list 1106 or connection sets list 1107, uponreceipt of such a request, parses its available objects list andforwards the message correspondingly to a movie object, menu object orconnection list object, and so on, until the message is received by alast recipient object. The last recipient object then retrieves therequested data and sends the data in the reverse direction of requestreceipt until the data reaches volume 1100. Volume 1100, upon receipt ofthe data, sends the requested data to authoring engine 160. (Errorhandling and messaging functionality are otherwise handled in aconventional manner.)

Data management engine 165 further responds to queries from authoringengine 160 for purposes such as totaling the number of data elements ofa given type or for reviewing the contents of a particular object's datalist. As with data storage and retrieval above, data management engine165 receives a call from authoring engine 160 requesting information.Volume 1100 parses the message, polls its available objects list andsends the message to a corresponding object. For objects linked to atree-structure, such as movies list 1105, menus list 1106 and connectionsets list 1107, the message is forwarded down through respective objectsas already discussed, and a last recipient object will respond. If themessage requests, for example, a total number of data elements of agiven type, then a last recipient will either poll its totals variableor, if necessary, poll its data list for corresponding data, count thenumber of corresponding occurrences and return a response including thetotal. The response is sent back through the tree structure to volume1100, which sends the message (including the total) to authoring engine160. Given the relatively small number of objects, alternatives (such asasynchronous multiple-messaging and, in particular, broadcast messages)add some expediency, but with unnecessarily added complexity.

As with the authoring engine interface objects, the object types,inter-object messaging protocol and data objects utilized in datamanagement engine 165, in view of the disclosure herein, will beapparent to those skilled in the computer arts. Preferably, availableobject libraries from Microsoft® are utilized. For example, thepreferred available objects and data lists utilize Standard TemplateLibraries and, in particular, Expandable Indexed Buffered/VectoredLists. Such objects provide robust response with the flexibility ofexpandable lists and indexed vectors for easy lookup in light of thetypically small number of objects and datasets, among other factors. Asnoted earlier however, use of an object-oriented architecture and/or thespecific data structures are not essential and many conventionalalternatives can be utilized.

As discussed, the particular arrangement of objects of the preferreddata management engine 165 is preferred according to its flexibility,performance and adaptability among other factors. It should be notedtherefore, that any number of modifications will be apparent accordingto the teachings and within the spirit and scope of the invention.

FIGS. 12 a through 15, with reference to FIGS. 2 and 11, illustratecompilation according to a preferred embodiment of the invention.

As shown generally in FIG. 12 a, compiler 170 (FIG. 2) preferablyoperates on data entered through the authoring process into theinterface 160 a of authoring engine 160 (FIG. 2) and stored by datamanagement engine 165 in three stages. In step 1201, compiler 170 buildsan intermediate skeleton-form PGC layout data structure. Theskeleton-form PGC layout data structure is preferably formed accordingto DVD program code segment (“program chain” or “PGC”) abstractions anda network abstraction according to the invention, utilizing only summarydata gathered from data management engine 165. Broadly stated, each PGCabstraction is preferably comprised of pre-determined commandcombinations, wherein the number of PGCs of a given type and the numberof command combinations of a given type (e.g. button commandcombinations) are determined according to either a default value (e.g.typically one PGC) or according to the number of corresponding authoredelement types. (e.g. the number of menu buttons in a given menu).

In step 1203, compiler 170 resolves source-target connections as indicesto source and target identifier information within data managementengine 165. In step 1205, compiler 170 replaces the indices withidentifier information which is retrieved by further querying datamanagement engine 165.

FIG. 13 illustrates a preferred PGC layout structure according to theinvention. As shown, the PGC layout structure is divided into a singlefirst play PGC space 1301 (in accordance with the DVD Specification), asingle video manager (“VMGM”) domain 1302, and one or more video titleset (“VTS”) domains (e.g. 1303 and 1304) according to the number ofmovies in the movie title.

The preferred VMGM domain PGC layout structure includes a single titlekey PGC abstraction, 1321 and a single movie router PGC abstraction1322. Thereafter, the VMGM PGC structure includes 2 menu PGCabstractions (e.g. 1323 a and 1323 b) for each authored menu and asingle PGC abstraction for each end command (in each movie) that anauthor for which an author has specified a connection. As will bediscussed further, each menu PGC abstraction pair includes a menudisplay PGC (e.g. 1323 a and 1324 a) and a menu button router PGC (e.g.1323 b and 1324 b).

Each VTS domain PGC layout structure (e.g. 1303) includes a moviedisplay PGC 1331 and a video title set menu (“VTSM”) area 1332. VTSMarea further consists of from one to four remote key router PGCs (e.g.remote key router PGCs 1332), depending upon the number of differentremote key commands necessary, given the preferred layout structure, torealize the chapter target connections selected using connection view901. More specifically:

-   -   number of remote key router PGCs in a given VTSM=total number of        chapter points in a corresponding movie/25 (rounded, if a        non-integer, to a next higher integer value).

In each case, an attempt has been made to minimize the number of PGCswithout detrimental impact on flexibility. Thus, while the number ofPGCs is as indicated above, complete authoring flexibility with regardto connecting menus, menu buttons and presentation data without concernfor limitations of the DVD programming specification 207 (FIG. 2) isprovided. Further, the practical impact of resultant limitations is alsominimized.

For example, the number of remote key router PGCs per VTSM areacalculation reflects that each chapter point abstraction requires morethan four commands. This in turn reflects that only one hundred twentyeight commands are allowable in a single PGC chain in accordance withthe DVD programming specification 207. While not essential, placing eachabstraction completely within a separated chains and in equal numbersthroughout like chains provides an efficiently symmetrical structure.Since DVD programming specifications 207 provide for up to ninety ninechapter points per movie, a maximum of four PGC abstractions is requiredwithout detrimental impact in terms of connectability. Considering thesame parameters and calculations for menus however, it is seen that onlytwenty five menu buttons are available per menu without limitation onconnectability. In practical terms however (i.e. displaying a menu on aconventional television set), this number does not present any practicaldetrimental effect.

The use of consecutive locations in the PGC layout structure greatlysimplifies the task of finding specific PGCs relating to specific datatypes and further for resolving PGC connections. A movie title PGC willalways be the first element, a movie router PGC will always be thesecond element, and a display menu PGC can always be located merely byadding a known constant plus two times the menu number, etc.

Those skilled in the art will appreciate however, in view of thediscussion herein, that the PGC abstractions provide for other thanconsecutively arranged elements as an indexed list in memory 120 (FIG.1). Such alternatives, for example, include but are not limited tomultiple lists, queues and/or multi-dimensional arrays stored in memory,in other media, and/or in more than one media either locally or in adistributed fashion, as with data management engine 165. Such methodscan be useful where more than one authoring location or otherdistributed environments are utilized.

The FIG. 12 b flowchart, with reference to FIG. 13, shows in greaterdetail how compiler 170 constructs a preferred PGC layout data structurein an initial skeleton form. As shown, compiler 170 begins by storing afirst play PGC abstraction, a title key PGC abstraction and a menurouter PGC abstraction into PGC layout structure 1300 (FIG. 13) in steps1207, 1208 and 1209 respectively. Next, in step 1213, compiler 170queries data management engine 165 for a total number, MenusTot, ofmenus authored and, in step 1214, initializes a menu pointer, MenuPtr.In step 1215, compiler 170 queries data management engine 165 for atotal number, ButtonsTot, of buttons authored in a current menu (e.g.initially, a first menu). MenusTot will specify the number ofpre-determined menu display and menu button router PGC abstractions(i.e. “menu PGC abstraction pairs”) that compiler 170 will add to thestructure, while ButtonsTot will specify the number of commands thatcompiler 170 will add to each PGC of a current menu PGC abstractionpair.

In step 1216, compiler 170 adds a menu PGC abstraction pair to VMGM PGCstructure 1302 (FIG. 13) corresponding to the existence of and thenumber of buttons in a current authored menu (e.g. initially, a firstmenu). If, in step 1217, one or more menus are not yet added to VMGM PGCstructure 1301, then in step 1218, compiler 170 increments the menucounter and returns to step 1211.

At this point, compiler 170 lacks any authoring information other thanMenusTot and a respective ButtonsTot value for each current menu. Asimilar same lack of further authoring details will also exist for otherPGCs in the skeleton-form, PGC layout structure. The preferred PGC andnetwork abstractions of the invention however, enable compiler 170 toaccommodate missing authoring details merely by inserting null values(“no-ops”) into the commands of the abstracted PGCs for unknownconnection information (i.e. source-target identification information).As discussed, compiler 170 will preferably resolve these no-ops later incompilation. These abstractions further enable menu PGCs to be createdindependently of movies and movie arrangements. Thus, independentlycreated/conceived menu PGCs provide extensive flexibility, allowing anauthor to link any available menu button of any menu to any potentialtarget using a user-friendly interface such as the preferred connectionview 901.

If instead, in step 1217, all authored menu layouts are reflected bycorresponding menu PGC abstraction pairs, then compiler 170 proceeds tostep 1219. In step 1219, compiler 170 queries data management engine 165for the total number, MovieTot, of movies, which compiler 170 will useto create end commands, VTSs and VTS contents. In step 1221, compiler170 initializes a current movie pointer (“MoviePtr”), as well as twocounters, “EndTot” and “Remote”. Compiler 170 will use EndTot to countthe number of available end-of-chapter conditions in each movie forwhich an author has specified connections and will use Remote to countthe number of available playback interruption conditions (i.e. by a userpressing a DVD-player control, typically on a remote control device) forwhich an author has specified connections.

In step 1223, compiler 170 queries data management engine 165 for thetotal number of chapters (“ChapterTot”) in a current movie (e.g.initially, the first movie) and, in step 1225, initializes a currentchapter pointer (“ChapterPtr”). If, in step 1227, the author hasspecified a target for the current chapter, end-of-chapter condition(i.e. using connection view 901), then, in step 1229, compiler 170increments EndTot; otherwise, compiler 170 proceeds to step 1231.Similarly, if, in step 1231, the author has specified a target for thecurrent chapter, remote-control key playback interruption (“remote-key”)condition, then, in step 1233, compiler increments Remote; otherwise,compiler 170 proceeds to step 1235.

The existence of authored connections is determined similarly for bothend-of-chapter and remote-key conditions. Preferably, objects 1101–1163(FIG. 11) contain actual source and target identifier information (i.e.corresponding to authored sources and targets), while the connectionobjects (e.g. 1171 a) contain pointers to data stored by these objects.Stated alternatively, as a new potential source is authored, aconnection object is instantiated, including a source pointer thatpoints to the potential source and a null-value target pointer; if anauthor later connects such a source, then the correspondingconnection-object target pointer value is replaced by a pointer to thetarget object. (Subsequent editing by an author correspondingly deletesor instantiates a connection object and/or changes a source pointer ortarget pointer value.)

Therefore, compiler 170 determines the existence of a connected endcommand by first querying each connection object for a source pointerpointing to the currently selected chapter-object. Once found, compiler170 checks the corresponding target pointer. A null-value target pointerindicates an unconnected end command while a non-null-value targetpointer indicates the existence of a connection. Remote key (i.e. “menukey” in FIG. 11) connections are similarly determined by finding anidentifier in a current chapter menu key object (e.g. 1157), finding thecorresponding source pointer in one of the connection objects, and thenquerying the connection object for the existence of a correspondingnon-null-value target pointer.

Those skilled in the art, in view of the foregoing, will appreciate thatconsiderable variation of the above structure will provide the same,related or similar functionality. For example, identifiers, labels andeven complete movie tree, menu tree and/or other objects could well becontained within or duplicated within the connections-tree (i.e. objects1107–1173). A single connection object could also be used (i.e. having asingle list of all connections), as could connection objects that remaindespite the deletion of a source. Other variations are also anticipated.The current structure is however, preferred in that it provides acompilation time of only a few milliseconds, minimizes memory usage andfurther facilitates debugging, emulation, simulation and overallsymmetry by separating these objects (and their contained data). Insimulation, for example, the restrictions imposed by the DVDSpecification are not controlling and simulation can therefore moreefficiently utilize authoring data directly from the preferred,non-integrated data management engine 165 object structure.

Returning now to FIG. 12 b, if, in step 1235, more chapters remain inthe current movie, then compiler 170 increments ChapterPtr and returnsto step 1227; otherwise, compiler 170 proceeds to step 1237. In step1237, compiler 170 adds a 1–4 PGC, end command router PGC abstraction tolayout structure 1300 (FIG. 13). In step 1238, compiler 170 creates aVTS domain for the current movie (i.e. including a VTSM), adding to theVTS domain a movie display PGC in step 1239 and adding a 1–4 PGC, remotekey PGC abstraction in step 1240.

If, in step 1241, more movies remain in the current movie title (i.e.tested by comparing MovieTot with MoviePtr), then compiler incrementsmoviePtr in step 1243, re-initializes EndTot and Remote in step 1245 andreturns to step 1223. Otherwise, formation of a PGC layout structure inskeleton form has been completed.

The FIG. 12 c flowchart with reference to FIG. 11 shows how compiler 170replaces the no-ops in (skeleton form) PGC layout structure 1300 withindices (i.e. source or target pointers) to respective sources andtargets, and then further replaces the indices with element identifiers.In step 1251, compiler 170 initializes a movie pointer (“MoviePtr”) to afirst movie, a chapter pointer (“ChapterPtr”) to a first chapter, a menupointer (“MenuPtr”) to a first menu and a button pointer (“ButtonPtr”)to a first button.

In step 1253, compiler 170 queries data management engine 165 (i.e.connection-objects) for a source-pointer to a next (initially, a first)author-connected button. As discussed earlier, the connection objectchecks its source-pointer for a corresponding source having acorresponding non-null-value target pointer. Since specific connectionvalues (rather than the existence of a connection as with FIG. 12 b) arerequired in this case, the query utilized results in the return of sucha source-pointer. In step 1255, compiler 170 uses the returnedsource-pointer to query data management engine 165 for the correspondingtarget-pointer and, in step 1257, compiler 170 uses the returned indicesto query data management engine 165 (e.g. via volume 1100, menu-1 1160 aand button list 1161 to button-1 1162 a) for the source and targetidentifiers corresponding to the source and target pointers. Then, instep 1259, compiler 170 replaces the current button command no-ops (ofthe current menu PGC abstraction pair) with the returned identifiers.

If, in step 1261, more buttons remain unresolved in the current menu,then compiler 170 increments ButtonPtr in step 1263 and returns to step1253; otherwise, compiler 170 proceeds to step 1265. If, in step 1265,menus remain unresolved, then compiler 170 increments MenuPtr and resetsButtonPtr to one in step 1267, and then returns to step 1253; otherwise,compiler 170 proceeds to step 1271.

Having resolved and replaced all menu button no-ops, compiler 170 nextresolves all chapter end-command and remote-key PGC abstraction no-opsin a similar manner. Compiler 170 queries data management engine 165 fora (next connected) current chapter end command source-pointer in step1271, uses the returned source-pointer to query data management engine165 for a corresponding target-pointer in step 1272, uses the pointersto query data management engine 165 for corresponding identifiers instep 1273 and replaces corresponding layout structure 1300 PGC commandswith the returned identifiers in step 1274. Similarly, compiler 170queries data management engine 165 for a (next connected) current remotekey source-pointer in step 1277, uses the returned source-pointer toquery data management engine 165 for a corresponding target-pointer instep 1278, uses the pointers to query data management engine 165 forcorresponding identifiers in step 1279 and replaces corresponding layoutstructure 1300 PGC commands with the returned identifiers in step 1280.

If, in step 1283, more chapters remain unresolved, then compiler 170increments the chapter pointer in step 1285 and returns to step 1271. Ifinstead, no chapters remain unresolved in the current movie, thencompiler 170 proceeds to step 1286. In step 1286, compiler 170 queriesdata management engine 165 (i.e. via volume 1100 to media database 1103of FIG. 11) for all audio and video file references which reference thecurrent movie. In step 1287, compiler 170 invokes multiplexer 185, whichretrieves the referenced audio and video files and outputs a resultantmultiplexed data file in a conventional manner and in accordance withthe DVD disk format specifications 205 (FIG. 2) of the DVDSpecification.

If, in step 1288 more movies remain unresolved in layout structure 1300,then compiler 170 resets pointers for the next movie and first chapterin step 1289 and returns to step 1271. Otherwise, compiler 170 (in asimilar manner) resolves first play, title key jump source and menurouter no-ops respectively in steps 1291, 1293 and 1295. Then, in step1297, compiler 170 saves the PGC layout structure as a stored file.

With regard to FIGS. 12 b and 12 c, total authored element values (i.e.such as MenusTot and ButtonsTot) are maintained on an ongoing basis in acorresponding list object or the functional equivalent of a list objectas already discussed. For example, movies-list object 1105 (FIG. 11), inaddition to a list for containing references to all instantiated movieobjects, also contains a variable for updating the total number ofmovies in a current movie title during the course of one or moreauthoring sessions. Similarly, button-list object 1161 contains a listof instantiated button objects (e.g. 1162 a through 1162 b) as well as avariable indicating the total number of buttons in menu-1. Other listobjects similarly include ongoing totals which are updated during thecourse of authoring. One reason is that some early-generationDVD-players limit the available memory space for storing PGCs, whichcorrespondingly limits the number of elements (e.g. menus, menu buttonsand chapters) that the invention permits to be authored. These limitsand/or current totals are therefore selectively conveyed to an authorthrough interface 160 a. Ongoing totals are also beneficial in that notime periods are required during compilation for calculating suchtotals.

As will be understood by those skilled in the art however, total valuesmight become unimportant for other than compilation purposes asDVD-players are manufactured with increasing resources in conformancewith the current DVD Specification, in accordance with expanded DVDcapabilities and in accordance with the requirements of non-DVD systems.In such cases, totals can alternatively be calculated duringcompilation.

The use of preferably pre-determined PGC abstraction types comprisingpreferably pre-determined command combinations and the preferred PGClayout structure are thus factors in providing a maximized authoringflexibility and efficient compilation among other benefits. Availableconnections remain completely flexible during authoring and, in fact,until substitutions are made for no-ops during compilation. Thepreferred structures of PGC abstractions further add to compilationefficiency, since a skeleton can be formed with only summary authoringdata, and then authoring details can be quickly added thereafter.

FIGS. 14 and 15, with reference to FIG. 13, illustrate a preferrednetwork or “connection-switching” abstraction according to theinvention. The connection-switching abstraction, while operationallyactive only during playback of a movie-title, is also a factor indetermining PGC abstractions produced by compiler 170 as well as themovie, menu and connection movie-title abstraction utilized by datamanagement engine 165, interface 160 a and authoring engine 160 (FIG.2).

Details of the DVD Specification including but not limited tomultiplexed data stream and DVD player configurations, data formats,protocols and loading of data are known to those skilled in the art andwill therefore be discussed only to the extent required for anunderstanding of the invention.

DVD programming specifications 207 (FIG. 2) provide that PGCs can reside(along with the corresponding presentation data) in virtual structuresincluding a first play space, a video manager (“VMGM”) and any of 99video title sets (“VTSs”), each of which includes a video title set menuspace (“VTSM”). Among the limitations of this virtual structure however,is first that a PGC in an initial VTS or VTSM cannot directly trigger(i.e. jump to, using a DVD jump command) a PGC stored in another VTS (orVTSM). For example, while a PGC in an initial VTS can “playback achapter of presentation data” and the conclusion of chapter playback cantrigger a “followup” PGC, the followup PGC cannot be stored in adifferent VTS. Similarly, an initial PGC used to respond to DVD consumermenu-button activation cannot trigger a second PGC which is stored in adifferent VTS. A further relevant limitation is that the format ofperformance data must remain constant within a given VTS. So, forexample, a video data stream having one aspect ratio cannot be stored inthe same VTS with another video data stream having a different aspectratio.

The FIG. 14 functional diagram illustrates how the preferredconnection-switching abstraction provides a flexible and robustfunctional superstructure within which movie-title, DVD-player andinteractively occurring consumer-control events are routed and executed.In the figure, VTS-A 1303 and VTS-A+1 exemplify any two different VTSswhich have been created during compilation of a movie-title. It shouldalso be noted that the illustrated connection arrows only denote the“path” from one box (i.e. PGC abstraction, PGC or command-set) toanother that can result from an author's use of connection view 901(FIG. 9). Thus, fewer connections than those illustrated might beauthored and each path from one box to another is accomplishedindividually using a single “jump command” or a single transfer ofcontrol by a DVD-player. (The use of multiple connected arrows andshared arrows is used only for clarity sake, since the alternative useof individual arrows between each pair of boxes might otherwise obscurethe invention.)

Within each VTS, only a movie display PGC abstraction operates as a“control PGC” (i.e. directly controls menu and/or movie display). Forexample, VTS-A 1303 includes movie display PGC abstraction 1331 and(within its VTSM domain 1322) remote key PGC abstraction 1322 a. Moviedisplay PGC abstraction 1331 comprises a single PGC which includes acommand-set (“pre-command”) for selecting a chapter and initiatingplayback of the chapter, as well as an end command “cell command” thatinitiates routing upon the occurrence of an end-of-chapter-playbackcondition. Remote menu key 1431 a, which denotes an automatic DVD playerfunction, traps and forwards a remote-key condition (i.e. userdepression of a remote menu key which interrupts playback). Remote menukey router PGC abstraction 1322 a of VTSM-A 1322 sets the authoredtarget for a corresponding remote menu key condition (i.e. where aconsumer presses a remote menu key during playback) and then routescontrol to a corresponding movie PGC abstraction or menu PGC abstractionwithin VMGM 1302. Other VTSs (e.g. VTS-A+1 1304) are similarlystructured for each movie within the current DVD movie-title.

Each remote menu key router PGC abstraction includes up to 4 PGCs toaccommodate the up to 99 chapter points per movie limitation of the DVDSpecification. The first remote menu key PGC is always assigned as aroot menu and is always a hardwired (i.e. unalterable) target for anyremote menu key condition (in accordance with the DVD Specification).Therefore, in order to provide for chapter dependent routing of a remotemenu key condition, a DVD-player system register must first be queriedfor the last played chapter. Using the returned last played chapterinformation, program execution is then diverted to the correspondingauthored remote menu key router PGC.

VTSM 1302 comprises the discussed menu display PGC (e.g. 1322) and menubutton router PGC (e.g. 1323 b) abstraction pairs (for providing menucontrol), as well as the remaining router PGC abstractions. Morespecifically, movie router PGC abstraction 1322 acts as a playbackbridge between VTS domains, receiving control from a remote key PGC in afirst VTS (e.g. remote key PGC 1322 a of VTS 1303) and then forwardingcontrol to a movie display PGC abstraction in second VTS (e.g. movieplay PGC 1341 of VTS 1304). In contrast, end router PGC abstractions(e.g. 1325 and 1326) can be author-connected to route control from anend-of-chapter condition to either a selected chapter in a selectedmovie, or to a selected menu button in a selected menu.

As shown, a separate PGC is provided for each author-connectedend-of-chapter condition. Each end command router PGC abstraction ispaired with (i.e. responds to) a specific end command such that eachend-of-chapter condition for a given movie will be routed from the endcommand to a unique end router PGC abstraction. Separate end commandPGCs are required due to a flaw in current generation DVD-playerswhereby the last played chapter is not reliably available at the end ofchapter playback. Upon correction of this flaw in future generationDVD-players however, end command routing can be accomplished in a mannerconsistent with remote menu key PGC abstractions (i.e. using only up tofour end-command router PGCs per movie).

A menu display PGC abstraction (e.g. 1323 a), when it receives controlas a target and thereafter while a consumer continues to depress menunavigation buttons, effectuates control by highlighting a menu buttonand displaying the menu. If however, a consumer activates a menu button,then the DVD-player initiates the corresponding router PGC abstraction(e.g. 1323 b), which routes control (i.e. according to an authoredconnection) to either a movie display PGC or to a menu display PGC.

For clarity sake, the first play PGC abstraction 1301 and title key PGCabstraction 1321 (FIG. 13) are not shown in FIG. 14. Each operates totransfer control to either a menu display PGC or a movie display PGC aswith the end command router PGCs and menu router PGCs. First play PGC1301 is stored in a separate DVD-player storage location, while titlekey PGC 1321 is stored in VMGM 1302.

While those skilled in the art will appreciate, in view of thediscussion herein, that considerable variation might be utilized,iterative experimentation with different connection-switchingabstractions and DVD players has revealed a number of considerations.For example, command execution delays will necessarily occur as a resultof PGC execution and greater delays typically result from transfer ofcontrol between a VTS (e.g. 1303 and 1304) and VMGM 1302. Anotherexample is that a delay occurring prior to the start of a movie isobserved to be more acceptable than a similar delay during navigationthrough what can be a large number of menus. A still further example isthat consistent delay periods for similar transitions is more acceptablethan inconsistent delays for similar transitions.

Thus, the preferred connection-switching abstraction provides agenerally symmetrical structure wherein delays are first minimized bysource-router-target execution paths having a minimum number of PGCs andPGC commands. Movie display PGC abstractions are further placedsimilarly within each VTS, while menu PGC abstraction pairs are placedsimilarly within VMGM 1302. (Note that an author typically only connectsthe end command of a last chapter within any given movie, such that theDVD-player will continuously play all chapters with the movie beforecontrol is routed outside the corresponding VTS). In addition, movierouter 1322 is only used for VTS-to-VTS transitions This reflects, forexample, that inconsistent delay between movie-to-movie playback andmenu-to-movie playback is more acceptable than imposing further delay onmenu-to-movie playback or other alternatives. (For example, furtherdistribution and/or re-distribution of movie and/or menu routingfunctions have been observed to produce subjectively less acceptableresults.) In addition, movie router 1322 complexity and PGC length istherefore reduced. It should be understood however, that these alreadyshort delay periods will further decrease as advances are made inDVD-player technology and that the resulting decreasing importance ofsuch considerations might well contribute to furtherconnection-switching abstraction variations.

The FIG. 15 flowchart broadly illustrates the operation of preferredconnection-switching abstraction 1400. In step 1503, first play PGCabstraction is invoked in response to insertion of a movie-title into aDVD-player. The first play PGC abstraction (i.e. now the current PGCabstraction) determines target information (i.e. a target identifierand, if needed, target parameters). If, in step 1505, a router isrequired, then, the current PGC abstraction routes the targetinformation and control to a next router abstraction in step 1507 andoperation returns to step 1511. If no router is required in step 1505,then, in step 1509, the current PGC abstraction routes the targetinformation to the target PGC abstraction.

If, in step 1511, the target is not a chapter (i.e. playback of achapter is not the resultant authored event) then the target displays amenu (i.e. according to the target information) in step 1513 and theDVD-player waits for a menu button to be selected (i.e. step 1513through 1515 act as a wait loop). If, in step 1515 a menu button isselected, then the current PGC abstraction sets authored targetinformation for the selected button in step 1517 and operation returnsto step 1505.

If instead, in step 1511, the target is a chapter, then the targetinitiates playback of the chapter. If further, in step 1525, a consumerinvokes the remote menu key during playback of the chapter, then thecurrent PGC abstraction sets authored target information in step 1527and operation returns to step 1505. If, in step 1525, the remote menukey is not invoked (i.e. the chapter plays uninterrupted to itsconclusion) and a chapter end command target has been authored, then thecurrent PGC abstraction sets the authored target information in step1537 and operation returns to step 1505. If, in step 1535, a chapter endcommand target has not been authored, then operation continues in step1545.

If, in step 1545, more chapters exist in the current movie, then the DVDplayer increments the chapter number in step 1543 and operation returnsto step 1523. If instead, in step 1545, no more chapters remain unplayedin the current movie, then the player suspends playback and (in somemodels) switches itself off.

For clarity sake, the operation of preferred connection-switchingabstraction 1400 will also be discussed, by way of example, withreference to FIG. 14. If, for example, an authored-connection for firstplay is set to begin playback of a first chapter of a first movie storedin VTS-A 1303, then upon insertion of the DVD movie-title into aDVD-player, movie display PGC abstraction 1331 will be invoked. Moviedisplay PGC 1331 will select and initiate playback of the first chapter.

If the first chapter playback is interrupted by a remote menu keycondition, then the DVD-player will automatically trap the condition(i.e. box 1431 a) and will initiate the root menu PGC of remote menu keyrouter 1322 a of VTSM-A 1322. Assuming further that less than 25chapters exist in the first movie, the root menu PGC of remote menu keyrouter 1322 a (i.e. now the current source PGC abstraction) will set theauthor-selected target for the first chapter remote menu key conditionand will route control to either movie router 1322 or a menu display PGC(e.g. 1323 or 1324) within VMGM 1302. If movie router 1322 receivescontrol, then upon receipt, movie router further routes control to theauthor-connected movie display PGC, in this case, movie display PGC 1341of VTS-A+1 1304, which will set and initiates playback of theauthor-selected chapter of the VTS-A+1 movie.

If instead, playback of the first movie is not interrupted and only thelast chapter of the first movie includes an author-connected endcommand, then the DVD-player will continue to play successive chaptersof the first movie until the conclusion of the last movie. At theconclusion of the last movie, the DVD-player will execute cell command1431 b (i.e. end command), which will transfer control to the PGC in endrouter 1325 (in VTSM 1302) that corresponds with the chapter lastchapter played, i.e. the last chapter of VTS-A movie. (Since, in thiscase, only one chapter in the VTS-A movie has a connected end-of-chapterplayback condition, end router 1325 will include only the onecorresponding PGC.)

Upon receipt of control from end command 1431, end router 1325 (i.e. nowthe current source) will set the corresponding author-connected targetincluded in end router 1325. Assuming the target is the VTS-A+1 movie,end router 1325 will further route control to movie display PGC 1341 ofVTS-A+1 1304, which will set and initiate playback according to thechapter of the VTS-A+1 movie set by end router 1325. (Since control isnot being routed from one VTS to another VTS, movie router 1322 is notutilized.)

If instead, the current source PGC of end router 1325 (i.e. again, theonly PGC in end router 1325 in this example) includes an author-selectedconnection to menu N 1323, then end router 1325 will set targetparameters and will route control to menu display PGC 1323 a. Menudisplay PGC 1323 a will highlight the button of menu-N 1323 according tothe received target parameters and will then display menu-N 1323. Menudisplay PGC 1323 a will thereafter continue to be invoked by theDVD-player and will continue to highlight a button and display menu-N1323 correspondingly with each successive uninterrupted (i.e. byconsumer selection of a conflicting DVD control function) consumerdepression of a navigation button. If however, the consumer nextactivates a displayed menu button, then the DVD-player will invoke menubutton router PGC 1323 b. Once invoked, menu button router PGC 1323 bwill set target parameters according to the author-selected connectionfor the activated button, and so on.

Attachment A attached hereto provides computer listings of preferred PGCabstractions source code according to the invention. For clarity sake,compilation has already been completed. Stated alternatively, the no-opsinitially included in the skeleton-form PGC layout structure have beenreplaced by indices and the indices have been resolved to source andtarget identifiers using the discussed compiler and compilation methods.

As shown in attachment A, the preferred PGC abstractions utilize anumber of DVD player registers. According to the DVD specification, eachDVD player includes 16 general purpose registers (“GPs”), and 20 systemregisters (“SPs”). The GPs are functionally undefined and merely“available for use” by movie title control program PGCs. Conversely, theSPs have fully defined purposes consistent with DVD player operation andmovie title control program interfacing.

The preferred GPs utilization and corresponding naming conventionsaccording to the invention are indicated in the following chart. Asshown, PGC abstractions exclusively utilize only 5 GPs, leaving amaximized number of remaining GPs available for adding furthercapabilities.

Register Referenced as Description GP10 Stream Select Bit 15 = Selectaudio stream on/off Bit 14 = Select subtitle stream on/off Bit 13 =Select angle stream on, off Bits 10–12 = Audio stream number Bits 7–9 =Angle stream number Bits 0–6 = Subtitle stream number GP12 Target MovieNumber Stored number = Movie number GP13 Target Button Number Storednumber = Button number GP14 Target Chapter Number Stored number =Chapter number GP15 Temporary Register Stored number = value used withcurrent PGC SP7 Last Chapter Played DVD player fills the register withthe number of the last chapter played SP8 Last Highlighted Button DVDplayer fills the register with the number of the last highlighted button

As illustrated by the register utilization chart, GPs are utilized bysource PGC abstractions primarily for designating (i.e. resolving anavailable connection to) target PGC abstractions and for passing to thetargets parameters affecting target operation. The GPs are furtherutilized by target PGC abstractions primarily for establishing,manipulating and recalling localized variables (i.e. relating to acurrently executing PGC command set).

For example, at a time prior to initiating playback of a chapter, asource PGC abstraction stores a value in GP10 (“stream select”). Thatvalue will later indicate to a target PGC which audio, subtitle and/orangle stream is to be selected for movie playback. A further example isthat, at a time prior to routing control to a target PGC abstraction, asource PGC abstraction stores a target's designation in a combination ofregisters GP12 (“Movie Number”) and GP 14 (“Chapter Number”) for a movietarget or GP13 (“Button Number”) for a menu target. Finally, PGCabstractions preferably utilize GP15 to temporarily store values,typically for use within a current PGC operation.

In most cases, only a portion of a given register (“register bits”) areutilized, while conversely, a given register may be used for multiplepurposes, as seen in the utilization of GP10 in the register chart.Those skilled in the art will appreciate, given the discussion herein,that the preferred embodiment enables certain advantages. Among theseare that a single register or register set can be designated in allcases for similar purposes, thereby minimizing complexities, the numberof registers required and the number of commands required within a PGCwithout detrimentally affecting routing or parameter passingflexibility. Similarly, operations required to parse register datacontaining multiple data values are not needed. Other arrangementsconsistent with the teachings of the invention however, are likely inview of other applications facilitated by these teachings and inaccordance with the scope and spirit of the invention.

While the present invention has been described herein with reference toa particular embodiment thereof, a latitude of modification, variouschanges and substitutions are intended in the foregoing disclosure, andit will be appreciated that in some instances some features of theinvention will be employed without a corresponding use of other featureswithout departing from the spirit and scope of the invention as setforth.

1. A method for providing source-definable destinations usingpredetermined program chain (“PGC”) command structures comprising:storing, in a source PGC corresponding to an authored source event, atarget identifier corresponding to an authored destination event,wherein said authored source event is selected from a group comprisingcompletion-of-playback of a DVD movie chapter, interruption-of-playbackof a DVD movie chapter and activation of a DVD source menu button withina DVD source menu; initiating execution of said source PGC upon anoccurrence of said authored source event; causing said source PGC tostore said target identifier in a storage location, and to initiate arouter PGC, wherein said storage location corresponds to at least oneportion of at least one DVD general purpose register; causing saidrouter PGC to retrieve said target identifier and to initiate adestination PGC corresponding to said target identifier; and if saidauthored destination event includes a further destination event, thencausing said destination PGC to initiate a further destination PGCcorresponding to said target identifier, wherein said authoreddestination event comprises displaying a DVD destination menu, and saidfurther destination event comprises highlighting a DVD destination menubutton.
 2. A method according to claim 1 wherein said at least one DVDgeneral purpose register includes at least one of a audio stream,subtitle stream and angle stream which is to be associated with any DVDplayback.
 3. A method for providing source-definable destinationsaccording to claim 1, wherein said router PGC resolves an availableconnection from a DVD-player control instruction to a receiving programchain.
 4. An apparatus for providing source-definable destinations usingpredetermined program chain (“PGC”) command structures comprising: meansfor storing, in a source PGC corresponding to an authored source event,a target identifier corresponding to an authored destination event,wherein said authored source event is selected from a group comprisingcompletion-of-playback of a DVD movie chapter, interruption-of-playbackof a DVD movie chapter and activation of a DVD source menu button withina DVD source menu; means for initiating execution of said source PGCupon an occurrence of said authored source event; means for causing saidsource PGC to store said target identifier in a storage location, and toinitiate a router PGC, wherein said storage location corresponds to atleast one portion of at least one DVD general purpose register; meansfor causing said router PGC to retrieve said target identifier and toinitiate a destination PGC corresponding to said target identifier; andmeans for causing said destination PGC to initiate a further destinationPGC corresponding to said target identifier, if said authoreddestination event includes a further destination event, wherein saidauthored destination event comprises displaying a DVD destination menu,and said further destination event comprises highlighting a DVDdestination menu button.